Reducing the Risk of Nuclear War Taking Nuclear Weapons Off High Alert Twenty-five years after the end of the Cold War, the United States and Russia continue to keep many hundreds of nuclear weapons on high alert, ready to be launched in minutes. This alert status—frequently called “hair-trigger alert,” “launch on warning” status, or other synonyms1—allows both countries to launch missiles quickly in response to warning of an incoming nuclear attack, before the attacking missiles hit their targets. This Cold War–era policy is dangerous because it increases the chance of an accidental, unauthorized, or mistaken launch of nuclear weapons, as historical examples of false warning and other mistakes demonstrate. Growing tensions between the United States and Russia make it even more important to ensure that should a crisis develop—increasing the time pressure on decision makers and opportunities for misunderstandings—high alert status does not lead to a mistake that sparks an unintended nuclear exchange. In addition, the Chinese military has recently begun to argue that China should put its nuclear weapons on alert for the first time and build an early warn- ing system to detect an incoming attack. These steps would also increase the risk U.S. Air Force/Josh Aycock Air Force/Josh U.S. One of 15 missile launch control centers at Malmstrom Air Force Base in Montana. Under high alert, military personnel have only three or four minutes to decide if warnings of foreign launches are genuine. 1 The U.S. military refers to this status as “high alert,” “ready alert,” “day-to-day alert,” “launch under attack” status, or “prompt-launch” status. of mistaken launches, especially since history shows that false The Cold War Origins of High Alert alarms are more common early in the operation of a new warning system. U.S. nuclear policy is the largest external in- The policy of keeping nuclear weapons on high alert is fluence on Chinese nuclear policy. As a result, a U.S. decision a holdover from the Cold War. Both the United States and to eliminate prompt-launch options from its nuclear war Soviet Union feared the other country might launch a first plans and take its missiles off high alert could affect the inter- strike attack consisting of thousands of nuclear weapons in nal Chinese debate and help influence China to refrain from an attempt to destroy bombers and missiles before they could taking these dangerous steps (Kulacki 2015a). be launched. At that time, leaders in both nations were con- For these reasons, the United States should remove op- cerned about the vulnerability of their nuclear weapons and tions from its nuclear plans for launching missiles on warning command and control systems to such an attack. To make of an attack, and take its silo-based missiles off alert. These clear it could launch a devastating nuclear response even fixed land-based missiles are vulnerable to attack and there- after a first strike, each country kept some of its weapons fore U.S. decision makers would be under the most pressure on high alert so they could be launched in retaliation within to launch them on warning. The United States also keeps sub- minutes of an attack being detected rather than being marine-based missiles at sea on high alert, but these are not destroyed on the ground. vulnerable to attack so there would not be such pressure to launch them on warning. It is important that the United States remove rapid- The United States should launch options from its nuclear plans. This change would mean that it would not return its missiles to high alert status remove options from its in a time of crisis. nuclear plans for While it would be preferable for both the United States and Russia to take these steps, the United States should not launching missiles on wait for Russia to act. Taking U.S. land-based missiles off high alert and removing rapid-launch options from U.S. nuclear warning, and take its silo- plans would still reduce the risk of nuclear use and thereby based missiles off alert. increase national and international security. At the same time, the United States would maintain a robust deterrent against nuclear attack. In 1961, the United States began keeping nuclear-armed bombers in the air 24 hours a day so they could not be destroyed on the ground. It ended this practice in 1968 after several accidents involving the aircraft and their nuclear weapons made clear the dangers of this policy (Department of Defense BOX 1. 1981). The final straw was the 1968 crash in Thule, Greenland, Mistaken, Accidental, and of a U.S. bomber on airborne alert carrying four nuclear bombs, due to a fire on the aircraft. The conventional high Unauthorized Launches explosives in the bombs detonated, which dispersed pluto- nium over a large area surrounding the wreck (Sagan 1993). Under U.S. policy, only the U.S. president can order the The United States developed a system of early warning use of nuclear weapons. If the president is incapacitated, radars in the late 1950s that could detect attacking missiles there is a chain of command that would be followed. An early in their flight and provide 15 minutes or more of warn- unauthorized launch is a deliberate launch that would take ing of an attack. As a result, following the Thule accident, the place without a presidential order. It could be perpetrated United States replaced its airborne bombers with bombers by insiders (e.g., ordered by those in the chain of command with access to the launch codes) or by outsiders (e.g., kept on alert on the ground—armed and sitting on the runway through a cyberattack). A mistaken launch would be autho- ready to take off on warning of attack. rized by the president, but in response to a false warning Along with the development of long-range missiles that of an incoming attack. An accidental launch would not could be launched quickly—in particular the Minuteman and be deliberate, but would occur through a system error Titan II missiles—the early warning system also allowed the (e.g., a computer glitch). United States to put land-based missiles on alert starting in 1962. But the capability to quickly launch missiles came with 2 union of concerned scientists The United States and Russia each deploys 1,800 to 2,000 nuclear weapons, and each maintains roughly 900 missile- launched nuclear weapons on high alert. U.S. Air Force U.S. In another close call incident in 1961, two nuclear bombs fell to the ground in North Carolina when a bomber lost a wing. Neither bomb detonated, but multiple submarines at sea, which could move into range of their safety devices failed. According to Defense Secretary Robert McNamara, “By the slightest margin of chance, literally the failure of two wires to cross, a nuclear targets and be on alert within days. Most of Russia’s nuclear explosion was averted.” warheads on high alert are believed to be on its silo-based missiles (Kristensen and McKinzie 2012). a price. Unlike bombers, missiles cannot be called back or Both the United States and Russia have options in re-targeted after launch. Nor do they carry self-destruct their nuclear war plans for launching missiles quickly if they mechanisms to abort a mistaken launch. Once fired, the receive warning of an incoming nuclear first strike. Indeed, missiles will proceed to their targets. those options drive the requirement to keep missiles on Unlike the United States, the Soviet Union did not rou- high alert. tinely keep armed strategic bombers on alert—either airborne Britain and France maintain SLBMs at sea, but they are or on the ground. And it did not have a warning system to thought to be on lower levels of alert than U.S. and Russian allow it to place its missiles on alert until the early 1970s missiles. China currently keeps its nuclear warheads stored (Podvig 2001). separately from its missiles, and therefore its forces are com- In 1991, following the end of the Cold War and with pletely off alert. The other nuclear-armed nations—India, relations warming between the United States and Russia, Israel, North Korea, and Pakistan—also keep their weapons President George H.W. Bush ordered U.S. nuclear bombers off alert, with their warheads stored separately from their taken off alert, with their nuclear weapons stored separately delivery systems. from the bombers. These planes are no longer ready to take off within 15 minutes, but can still take off within 24 hours. Yet both countries continued to keep nuclear missiles BOX 2. on high alert. Launch Under Attack The Current Situation While launching quickly on warning of attack is typically The United States and Russia each deploys 1,800 to 2,000 called “launch on warning,” the United States instead calls nuclear weapons, and each maintains roughly 900 missile- such use “launch under attack.” It states that launch under attack is based on an “attack assessment that considers launched nuclear weapons on high alert. For the United and confirms warning information from multiple, inde- States, the alert forces include all but a few of its 450 silo-based pendent sensors” and “also considers the apparent intent intercontinental ballistic missiles (ICBMs), each armed with of the incoming attack in the context of the international one warhead, and a comparable number of warheads on situation” (Department of State 2015a). The implication submarine-launched ballistic missiles (SLBMs) on the four is that the United States would launch only if it knew that to five submarines that are kept within range of their targets.